1. Field of the Invention
The present invention relates to an ink, an ink jet recording method, an ink cartridge, and an ink jet recording apparatus.
2. Related Background Art
Ink jet recording involves allowing fine ink droplets to fly by virtue of various working principles to adhere to a recording medium, thereby forming an image, a letter, or the like. The ink jet recording has rapidly become widespread in various applications because it has the following characteristics. For example, the ink jet recording can be performed at high speed, generates low noise, facilitates multi-coloring, has high flexibility of a recording pattern, and eliminates the need for development and fixation.
In recent years, the ink jet recording has been requested to provide an image having high quality comparable to that of a silver salt photograph. In the ink jet recording, a full-color image is formed on the basis of substractive color mixture. That is, color reproduction is performed by using a yellow ink, a magenta ink, and a cyan ink as three primary color inks of printing. In other words, in order to realize a high-quality ink jet image, each of the yellow ink, the magenta ink, and the cyan ink as three primary color inks must have high brightness and high chroma.
However, when one attempts to represent an entire region of a hue by means of three primary color inks, even if the three primary color inks to be used each have good color developability, a color region to be represented by mixture of the three primary color inks does not have sufficient chroma, and hence a color reproduction region that can be represented may be insufficient. In view of the above, there has been proposed a method in which a color ink intermediate in hue angle in a hue space between adjacent two inks of the three primary color inks such as a red ink, an orange ink, a green ink, a violet ink, or a blue ink is used in addition to the three primary inks to perform image formation.
It has become also necessary that a printed matter obtained by means of ink jet recording can be stored for a long period of time. In other words, the printed product must have excellent weatherability of an image such as a discoloration resistance of an image due to sunlight, various illuminations, and the like (light resistance) or a discoloration resistance of an image due to an oxidative gas (for example, ozone, NOx, or SOx) present in a trace amount in the atmosphere (gas resistance).
To solve the above problems and to expand a color reproduction range of a yellow region, an azopyridone-type dye having a specific structure has been disclosed as a colorant having high color developability and excellent weatherability, and an ink using the dye has been also disclosed (see, for example, Japanese Patent Application Laid-open No. 2002-504613).